Dragoș Rotaru

Research engineer at @circle. Most of the time I tweet about cryptography, sometimes about others.

[Sergey Gorbunov @sergey_nog]

Post-quantum migration is a nightmare.

That's why @circle is building @arc with post-quantum protections from day one.

TLDR:

* Native post-quantum signature verification: Arc ships with an SLH-DSA-SHA2-128s precompile, enabling smart accounts to verify quantum-safe signatures on-chain today.

* Post-quantum account abstraction: Developers can build ERC-4337 wallets that use post-quantum signatures immediately, without waiting for protocol-level transaction signature changes.

* Quantum-safe privacy by default: Arc’s privacy layer encrypts transactions, state, and execution using hybrid post-quantum cryptography (X-Wing, ML-KEM, PQ TLS), protecting against harvest-now-decrypt-later attacks.

* Post-quantum encrypted messaging: Transaction memos support HPKE + X-Wing encryption, giving developers a standardized way to exchange quantum-safe encrypted data on-chain.

* Migration tools for existing assets: Arc introduces mechanisms such as PQ public-key registries, hash-and-rotate wallets, smart-account upgrades, and a proposed post-quantum replacement for ecrecover to help existing contracts and users migrate safely.

Read more: https://t.co/3S2oSIjS1k

[zkSecurity @zksecurityXYZ]

On May 15, THORChain was drained for ~$10.7M. Root cause: a flawed implementation of GG20, an MPC-based threshold signature scheme.
Theoretically sound MPC schemes keep failing in implementation. So we built a reference for it 👇

[Dragoș Rotaru @DragosRotaru]

@MMahzoun Sure, if only that 'minimal cryptography' holy grail would offer decent speed. Always depends on the usecase

[Chris Ries @chrisries]

Google’s 2029 PQ readiness timeline is a wake up call.

Arc is taking a holistic approach to deploying PQ cryptography including PQ wallet signatures on mainnet launch.

PQR is not zero-sum. The ecosystem needs to move together and we’re excited to help lead the way.

[Sergey Gorbunov @sergey_nog]

For the last 30 years we were always 5 years away from Quantum Computers.

But sentiment suddenly flipped. Technology is suddenly improving. In just the last couple of weeks, Google suggested Q-day could come as early as ~2029, and new research points to breaking ECC requiring far fewer qubits than previously thought.

We still don’t know when quantum will come to reality. But to me, one thing is more clear than ever - when it comes, it will be sudden.

For blockchains, dealing with quantum is both a blessing and a curse. Yes many, besides Bitcoin, support “upgrade” mechanisms. But migrating liquidity, wallets, and applications is a nightmare.

@arc is built with quantum threat in mind from day one. A practical roadmap allows to both support existing ecosystem of tools and apps built around ECC cryptography, but also have quantum-safe built-in mechanisms (like signatures and checkpoints) to keep assets bullet proof.

One of the most unique and interesting aspects of the architecture is that because @arc will leverage confidential compute subspace. Within that subspace, all assets, applications, and transactions will be private and PQ secure by default. So, for instance, you can still generate a traditional ECC key within the subspace, but because of the extra layer of PQ encryption build on top, the keys and interactions fully hidden from adversaries.

Stay tuned for more.

@jerallaire of @circle explains on @tbpn ⬇️

[Dragoș Rotaru @DragosRotaru]

@TomerAshur @alinush My bet is that they ask for a single round of beers.

[Dragoș Rotaru @DragosRotaru]

@cryptodavidw Lend your private data to the agents to let them do it. What can go wrong?

[Dragoș Rotaru @DragosRotaru]

@badcryptobitch @SmartCryptology We're not talking about connections at large scale but I find it good for explaining various error correcting algos

[Dragoș Rotaru @DragosRotaru]

@badcryptobitch @SmartCryptology Link here https://t.co/MkJarSbh6R

[Dragoș Rotaru @DragosRotaru]

@0x10d9e We adapt, we overcome 💪

[Dragoș Rotaru @DragosRotaru]

We now live in a world where an anagram (MCP) has become more popular than MPC.

[zkSecurity @zksecurityXYZ]

The first two known exploits against live ZK circuits just happened, and they weren't subtle underconstrained bugs.

They were Groth16 verifiers deployed without completing the trusted setup ceremony. One was white-hat rescued for ~$1.5M, the other drained for 5 ETH.

🧵

[Dragoș Rotaru @DragosRotaru]

@0x10d9e @badcryptobitch Yes, networking is hard to get it right and it also depends on the MPC model someone chooses to implement. 🥵

[David Wong @cryptodavidw]

We just announced zkao, been working on it for the last few months full time, it's our response to "auditors might go extinct in a few years".

After all, if we do go extinct, might as well be part of the problem.

Let's be reassuring though, the tool is not here yet. As we wrote in the past, we test it after every audit, and it constantly doesn't find (important) bugs we find in audits, and sometimes find really good bugs BUT thinks they're not impactful.

Every time we try to fix that to improve the tool :) It's been getting better and better so quickly!

It also finds a lot of false positives, and this is where we think we can bring a lot of value: we're not just another per-PR/commit review bot, we are trying to only surface important bugs that we can confirm.

This is an uphill battle from our side BUT we firmly believe this is how we provide true value to developers (instead of having them click through warnings).

Anyway, the tool is going to get better every week, because we will improve it, or because the models will get better. It's truly amazing to work on a product that improves for free due to research from the big LLMs :D

We're focusing on Circom for now, and we're onboarding early-access users. If you're interested in trying the tool, let me know!

[Circle @circle]

How will blockchains adapt to quantum computing?

Circle Research explains how the industry is preparing for Q-Day.

https://t.co/JL7aRHq8M0

[Dragoș Rotaru @DragosRotaru]

@cryptodavidw So New York needs more cats...

[Dragoș Rotaru @DragosRotaru]

@luhelminger @TACEO_IO Congrats! Amazing team you're building 🚀

[Simon Willison @simonw]

I wrote up some notes on two new papers on prompt injection: Agents Rule of Two (from Meta AI) and The Attacker Moves Second (from Anthropic + OpenAI = DeepMind + others) https://t.co/XypZTJFN98

[Dragoș Rotaru @DragosRotaru]

@socrates1024 Proof of work for bonechains